The 61-year-old added another entry to his lengthy and impressive curriculum vitae on Friday night when he began his reign as manager of the Republic of Ireland with a 3-0 friendly victory over Latvia in Dublin.
O'Neill had been out of the game since March when he was sacked by Sunderland, the club he supported as a boy, and the war of words in which he has become embroiled with successor Paolo Di Canio in recent days is an illustration of how deeply that cut.
However, his determination to succeed has never waned and even the disappointment of his time on Wearside cannot dim his enthusiasm.
O'Neill said: "That hunger is there from - it was there from starting out as a player, as an 18-year-old.
"I haven't felt any sort of changes. Of course there are ups and downs and everybody has experienced those things, but overall it feels the same."
Asked if he is still driven on by the same things which brought him into football in the first place, he added: "Very much so, and this is it: it's just raw enthusiasm for the game.
"Those things never change, really. The minute that they do change, that's when you want to re-assess things."
In the short-term, O'Neill will continue a whirlwind start to the latest phase of his career when he and his players fly out to Poland on Sunday ahead of Tuesday night's friendly in Poznan.
They will do so on a high having turned in one of their most convincing performances for some time against a Latvia side which did little to upset the script on a night when the smiles came back to the faces of Irish football fans.
O'Neill knows few of their future opponents will prove quite as submissive as Marian Pahars' men on a night when goals from Robbie Keane - the 62nd of his senior international career - Aiden McGeady and substitute Shane Long secured a comfortable win.
However, the manner in which Ireland played, with wingers Aiden McGeady and James McClean terrorising their markers and James McCarthy and Wes Hoolahan pulling the strings behind Keane, drew a line under the safety-first approach of Giovanni Trapattoni.
The Republic may not always be able to take the same aggressive stance against more dangerous opponents, but the knowledge that the ability to do so remains in the armoury is a comfort.
O'Neill said: "We can't get carried away with ourselves. Lots of things could happen.
"When the big games come in, it's a matter of having your best players available, and that might not always be the case.
"I felt the performance was excellent. I mentioned last night, there will be sterner tests than Latvia, but it was good.
"It was good to play, it was good for players to get a bit of confidence about themselves. I think they felt that with the crowd behind them as well, it was positive for a first game.
"You mentioned how important to win the game - of course, the winning of the match is vitally important."
Poland, who pushed England all the way before losing 2-0 at Wembley in their final World Cup qualifier last month, will provide very different opposition in a city where Ireland lost to Croatia and Italy during their ill-fated Euro 2012 finals campaign.
O'Neill will make changes - David Forde will definitely start in goal after Keiren Westwood got the nod against the Latvians - as he attempts to see as many of his players in action as possible.
But whichever 11 men pull on the shirts ahead of kick-off, the manager has warned them they will find the going significantly tougher.
He said: "Well, regardless of the performance and the result last night, I think anyone who saw them against England would say they are a very decent side, so I think we will have our work cut out."
O'Neill's selection could be determined in part by a series of injury concerns with West Ham defender Joey O'Brien due to undergo a scan on a hamstring problem, while Andy Reid and Sean St Ledger are also understood to be doubts.